System for cooling the charge flowing to internal-combustion engines



April 3o, 1946. Q APPEL 2,399,310

SYSTEM FOR COOLING THE CHARGE FLOWING TO AN INTERNAL-COMBUSTION ENGINE Filed Feb. 25, 1944 2 Sheets-Shleeb l INVENTOR, seaf/l/J, l

ATTORNEY.

Amai 3Q, ma @APPEL www SYSTEM FOR COOLING THE CHARGE FLOWING TO 4N INTERNAL-COMBUSTION ENGINE Filed Feb. 25, 1944 2 sheds-sheet 2 INVENTOR, oscar fipa,

ATTORNEY.

Patented Apr. 3o, 194e aan SYSTEM FOR COOLING THE CHARGE FLOWING TO INTERNAL-COMBUSTION I ENGINES Oscar Appel, Paterson, N. J.

Application February 25, 1944, Serial No. 523,848

6 Claims. (Cl. 12S-119) In the operation of a supercharger for an internal-combustion engine an incident thereof is the heating of the charge (as fuel-air, if a carburetor is used, or air, alone, if an injector is used) delivered by the supercharger, with consequent detonation in the engine, the heating and likelihood of detonation of course being greatest when the manifold pressure is high, as when the engine is operating under high power output. Superchargers are used considerably in combination, for instance, with air-plane internal-combustion engines using a fuel-air mixture, and the underlying object of this invention has therefore been to provide a system adapted for cooling that portion of the passaged means, as of a supercharger, through which at least the air of the charge flows whereby, when the engine is operating under high manifold pressure, the cooling will be derived from the fuel itself, pre-cooled (as refrigerated) for that purpose, and when some lower manifold pressure obtains, as when flying at high altitude and hence in colder atmosphere following the climb, or it may be also in warming up the engine, such cooling as is then required will be derived from the atmosphere. i

Given such a passaged means through which a charge is conveyed to an internal-combustion engine, my invention contemplates combining therewith a uid conducting system which shall include a container for cooled fluid fuel and a fluid conductor to which the container discharges and which itself discharges to said system (as to the conductor or to the container) and which includes, with a heat-receiving radiator in heat-receiving proximity t the portion of said means through Which at least the air of the charge flows, a heat-discharge radiator (as exposed to the atmosphere), both of which are relatively aft (i. e., relatively to the direction of flow) of the point at which the conductor discharges to said system, means to impel the fluid from the container and through the conductor, said conductor having, relatively aft of said point, a fuel delivery outlet (to be indicated) discharging to said lator or a pump, for maintaining the fuel-pressure at the outlet greater than such fuel-pressure in the passaged means itself. In the example herein set forth so much of the passaged means as includes the supercharger affords a common passage for the fuel and air, a carburetor being assumed to be used to provide a fuel-air mixture, but my invention, in view of the known indicated paSSag'ed means, and means, aS a, PIESSUI'B IGgll- I resort to an injector in place of aI carburetor, is not to be regarded as thus limited.

Having such a system and the impelling means Vcombined with said passaged means the iluid will be circulated in said system wherefore, with the iiuid pre-cooled (as refrigerated, or otherwise having a temperature lower than normal, i. e., lower than air temperature at surface level) the following advantageous conditions are possible:

While the-plane is on the ground, the engine merely being warmed up' and the impelling means operating at low effort, the necessity for cooling the supercharged air being low, a relatively little quantity of cold fluid (or it may be none as will hereinafter be evident from Fig. 5) will enter the conductor thus to lower the temperature of the iluid vcontinuously flowing therethrough,'and in any event at such time the receiving and discharge radiatorswould be effective in transferring heat from the compressed charge of the supercharger to the atmosphere (or rst by the receiving radiator to the circulating fluid and then by such fluid to the discharge radiator). But, with the impelling means operating'at high effort, these conditions will change since a correspondingly greater quantity of fluid from the kcontainer will then enter the conductor, thus correspondingly to lower the temperature of the circulating fluid. This is advantageous during the take-oil, for then the precooled iluid in the conductor is available to mix with andso cool the circulating fluid. Further when, the take-off being completed, level flying at high altitude ensues the said system will also function to cool, even if the fluid of the container may have meanwhile had its temperature somewhat raised vabove itsoriginal degree, since the discharge radiator, by its exposure to the colder atmosphere at the now high level, is then available to coact with the receiving radiator to deliver to the atmosphere such heat as the circulating fluid derives from the supercharged charge.

By the two radiators in the present example the heat accumulating in the passaged means is transferred to the fluid and then from the fluid to the atmosphere, or first via the receiving radiator and then via the discharge radiator,

wherefore they constitute means for so transferring the heat; and I claim accordingly in certain of the annexed claims. I

The invention may exist variously modified as will hereinafter appear and in accordance with the annexed drawings which illustrate the same conductor and the'.- other to the; container, there'.

being a valve toswitch the flow to either branch;

Fig. 4 shows a form like that of Fig. 1 excepting that between the pump P and the supercharger-containing portion M of` the passaged.

means, the conductor has branches-'by-passing each other and one of which contains the heatdischarge radiator R2, there being a valve to switch the flow to either such branch;

Fig. shows a form like that of Fig. 4. excepting that the branch, as 3, for conducting the fuel to the portion M contains a pump P formaintaining the pressure at the intake to such branch` greater than in the. branchit`se1`f';. and" Fig. 6 shows. a formlike. that off4,.with the heat-discharge radiator R2 contained. inv an air-chute.

Iny all the gures letMdenote thefsupercharger-containing` portion of the ypassaged means through. which portion the fuel as wellA as. the air in this example. ows to the engine,such charge being heated by compression'incident'to the supercharger, M being the intake to and M2 the discharge duct ofy said portion, the latter extending to-the engine. Saidpassaged means in this case also includes a fuel-feeding means' F; here assumed to beV a carburetor, discharging to intake M and having afuel feeding branch pipe 3 leading tosuch means. F. At F is the -fuel feedingmeans, here" assumed to be a: carburetor and thereforedischarging toY intake M. P is thepump or equivalent means for-impelling ther fuel. In all the 'gures there aree also.A the part T, R', R2 and 3l and (except. in Fig. 5) the` part PR to4 be referred to.

In Fig. 1 my sai'd system includes: a tank or other container T for: containingI the pre-cooledfuel and a fuel. conductor'- existing asfo'llows: I isl a pipe leading' from the c'zont'ai'nerTI and to which the latter discharges and which itself discharges. t'o the intakeside: of the pumpl P; and l!A is a pipe leading fromthepump and ,to which the' latter discharges, theV same beingcoiled' at Rf'to form a receivingradiatorandat R2 to formy a discharge radiator and saidpipe having its end remote from the container discharging to that portion of the conductor which is'v betweeny the container and? thepump, wherefore the portion of` the conductor whichincludes the radiators is developed endless. The fuel flow is as per the arrows shown. The receiving radiatorR" is: some such close proximity tothe passaged means M' (as here within it) thatthe heat of' the charge will be conveyed tothe fuel flowing through said radiator. Pipe 3, being connected to pipe 2, serves as a fuel-delivery branch discharging to the fuel-feeding'means F'. Radiator R2 is between radiator Rl andthe intake` end of the branch pipe, or, otherwise regarded, the outlet from the conductor,` to said branch. At PR; isl the meansA for maintaining the pressure in the conductor at the said intake of the branch, or such outlet. greater than in the branch itself and hence in the passagedmea-ns of whichsaid branch in this example forms a part, being. here any'pressure-regulator located ductor pipeY to which the container discharges pipe. I

aft of the branch in the direction of ilow through the system.

The pump being driven, fuel will be drawn from the container and caused to circulate via the endless part of the conductor, some of the iiowing fuel being diverted via the branch to the fuel feeding means F thereupon to form with air (in this example) the fuel charge which is to be compressedby the-supercharger and conveyed to the engine (such: diversion in thiscase being incident to the pressure-regulator) and such fuel asis thus diverted being constantly replaced in the conductor by fuel from the container T. If

' the fuel inthe container is therefore pre-cooled such as flowstherefrom to the conductor to mix with the fuel already in the conductor will absorb. heat from the latter that has been transferred thereto from the charge compressed by the supercharger. The system will therefore operate on warming-up the engine, on the takeoff and on level-flying on completion of the climb as. hereinbefore setV forth, the pre-cooled fuel' in the tank serving to cool during thev take-off' and the dischargeradiator serving, by transfer of heat; to the atmosphere, also. to cool, as on the level-flying atf the higher atmosphere, or it may be during the. latter part of the climb if the cold-fuel supply is exhausted and the elevation is such that the atmospheric temperature is low.

In Fig. 2 the conductor pipe corresponding to is designated 4. A conductor pipe 5, corresponding. to pipe 2 and here containing the two. radiatorsR and R2 and the pressure-regulator PR and having the branch 3 leading therefrom. to the fuel feeding means, has its end remote from. the container (or, as per the direction of now aftof the pressure-regulator) discharging to. the container. The-operation in this case is substantially thesame as in the Fig. 1 construction excepting that the temperature of the fuel .to the container; and at V is a valve, here rotary,

for switching the fuelfloW from pipe. 'lV to either of itsl branches` 'This construction is therefore in effect. a hybrid of. the Figs. 1' and 2 constructionsin that it maybe operated as'either of them is operated.

In the constructions so far described there is no. control ofthe dispensing of the. cold fuel in the container such as is afforded by the construction` shown by Fig. 4. In this case 8 is the conand which discharges to the pump P. From the latter. extends a conductor pipeV S, for apart ofits length between the pump and the radiator R existing as. divided into two portions 9aand' Sb ley-passing eachy other, thereafter including said radiator Rf and the pressure-regulator PR.- and;

having the` branch 3 tothe fuel feeding means, the. end ofV pipe 9- remote from the. container dischargingto that f portionaof the conductor 8' which is between the container and the pump. The branch 9b contains the radiator R2. At V' is a valve for switching the fuel via either of the branches 9a and 9b. While the engine is being warmed up or on the take-olf and during such part of' the climb as seems necessary the valve may be in the position shown, or so that the-flow from the pump and hence the container is via branch 3a. Thereupon the valve may be turned to switch the fuel to the branch 9b containing the radiator R2, as at level high-altitude iiying.

The construction of Fig. 5 embodies features similar to those of Figs. 3 and 4 and in this case the means for maintaining the pressure at the intake to the branch 3 greater than in the branch itself takes the form of a pump Pf for delivering fuel to the feeding means, thus: III is the conductor pipe to which the container discharges and which discharges tothe pump P. From pump P extends a conductor pipe I I, divided (as in Fig. 4) at I Ia and I I b to provide portions bypassingeach other and the portion IIb containing the radiator R2; and, relatively aft of these portions pipe II contains radiator R. and is then divided again (as in Fig. 3) at IIc and IId, portion IIc discharging to that portion of the conductor which is between the container and the pump P and portion Ild discharging, to the container. There is a valve V2 (corresponding to valve V' in Fig. 4) for switching the fuel via either of the portions lla and IIb and a valve V3 (corresponding to valve vV in Fig. `3) for switching the fuel to either of the portions Ilc and Ild. The branch 3 extends from pipe II] to the means F (the same asV corresponding branch extends from the corresponding pipes 2, 5, 1 and 9 in Figs; 1, 2, 3 and 4, respectively), but, instead of the'pressure-regulator being present therein, it contains the mentioned pump P' for maintaining the fuel-pressure at the outlet of pipe I0 to the branch 3 greater than the fuelpressure in the branch itself. 'Ihe two valves V2 and V3 are connected by a link I2 so as to be operated in unison. As shown the fuel flow via the conductor during the climb, as well as on warming-up and on the take-olf, is as per the solid arrows adjoining the conductor pipes I 0 and II and the portions IIa and IId; when levelflying, following the climb, ensues (or it may be during the latter part of the climb) the valves may be shifted so that the ow will be via pipes I0 and II, portions IIc and IIb and hence radiator R2.

In Fig. 6 the conductor is characterized the same as that in Fig. 3 in that there is the conductor pipe I3 to which the container discharges and which discharges to the pump and a conductor pipe I4 to which the pump discharges and which contains both radiators and from which, aft of the radiators,.the branch 3 leads to the fuel feeding means and aft of such branch there is the pressure regulator and aft of the latter said pipe is branched, as at I 4a and Mb, branch I4a discharging to the conductor between the container and pump and branch Mb discharging to the container, V4 being a valve corresponding in function to valve V of Fig. 3 or V3 of Fig. 5. (However, as to so much, the construction may be the same as in Fig. 1 or Fig. 2). But radiator R is in this case positioned aft of radiator R2 and the latter radiator is subject to cooling influence changeable at the will of the operator. Thus: An air-chute I5, ex-

tending lengthwise of the engine, is formed open at both ends but is provided with a pvoted damper IG'movable to permit or check the air-now through the chute, which contains radiator R2. This damper may be connected with valve V4 to move in unison therewith, as by the links I 'I and I8 and intermediate bell-crank lever I 9. On the take-olf, with the damper and valve in the positions shown, the fuel now is as per the solid arrows or so that such cooling as is required is derived from the cold fuel iiowing from the container. But on warming-up and for high-level flying the damper and valve are shifted so that (the damper being open) cold air may cool radiator R2 and the flow will be made to shortcircuit the container.

As will be apparent, so long as the radiators are in the endless `part of the system (i. e., excluding or including the container T in Fig. 1 or Fig. 2, for instance) the order of their arrangement is not material since in any such case the circulating body of fuel would have its temperature reduced either by-the colder fuel flowing from the container or by the cooling influence of radiator R2.

In the case where the conductor is branched and one branch discharges to the container and the other to the conductor, and there is a valve, as V3', Fig. 5, to direct the flow via either branch independently of the other, it will be apparent that no fuel will be drawn from the container into that part of the system which exists endless when the valve is turned to the position to direct lthe fiow via branch IIc.

Since the fuel is a fluid, and conceivably might be a gas, it is obviously not material that the conductor pipe in any of the forms shown provides forwithdrawal of the fuel at the bottom of the tank T. v

So long as the fuel-pressure, by suitable means (as PR or, in Fig; 5, the pump P), is maintained at the mentioned outlet by which the fuel enters the passaged means greater than such fuel-pressure in the passaged-means itself, it is not essential that the fuel be delivered to the engine with the air via a common passage of the passaged means.

Having thus fully described my invention, what I claim is:

1. In combination, with passaged means through which a charge is conveyed to an internal-combustion engine, a huid-conducting system including a container for cooled iiuid and a fluid conductor to which the container discharges and having discharge branches one of which discharges to the conductor and the other to the container, a valve for switching the fuel to either branch independently of the other, said conductor, aft of the point at which the one branch discharges to the conductor and anterior to said valve, including, with a heat-receiving radiator Vin heat-receiving proximity to said means, a heat-discharge radiator, and means to impel the uid from the container and through the conductor.

2. In combination, with passaged means through which a charge is conveyed to an internal-combustion engine, a huid-conducting system including a container for cooled iiuid and a duid-conductor to which the container discharges and which itself discharges to said system, whereby the latter exists at least in part endless, and such endless part including in one segment of its length a heat-receiving radiator ink heat-.receiifingz proximity' tcr seid. means; 'and`V having: another segment;- oi: its; lengthformed as two conductor; portions intr-passing. relation to. each other androne; of. which` includes a; heat,-

discharge radiator; akvalyef for switching'the fluid Via either off said portions; independently of theothel, and means to; impel thefluid from, the container and through theconducton 3. In. combination, with'. `passaged mea-ns` through which a` charge isv conveyed to an internal-combustion engine, a; fluid-conducting system including; a container' for cooled uid and a fluid-conductorto which the, container discharges andA having discharge; branches one of which discharges to the conductor and the other to the container, a valve for switching` theA uid viaeither branch independenthvfy of the other, said conductor, aft of the point at which the one branch discharges; to theconductor and anterior to the valve, includingin one segment of its length a heat-receiving; radiator in heat-receiving proximity to; said means-and having another segment of its'lengthformed as two, conductor portionsA by-passing each other and one of which includes a dischargefradiator, a valve for switching the uidivia either of said portions independently of the other, and means, aft of the point at which the conductor discharges to itself, to impel the. ud from the container and through the conductor.

4. 'In' combination, with passaged means through which aV charge is conveyedto-arr inter- I,nal-combustionA engine; a fluid-conducting system including a container forcooled fluid and a fluid conductor to,` whichv the container discharges and having;` discharge branches one oiv which discharges to the conductor and the other to the container, avalve for switching the uid to either branch independently of the other, said conductor, aft of the point at which the one branch dischargestothe conductor andanterior to said valve, including means to`V transfer tov theuid and thenfrom the` fluid` to` the atmosnhere the heat accumulating; in said passaged.

mea-ns, and means: to impel; thenuid; from the container and through the conductor.

5. In combination, with passaged `means through which, with air, a cooled fuel isl c onveyed. to. anv internal-combustion engine, a, conducting systemv including a container for the cooled fuelA and a fuel conductor to which, the container dischargesand which itself discharges tosaidsystem and includes, relatively aft of the' point at which the conductor dischargestoV said system, means to transfer to the fuel andthen from4 the fuelcto the` atmosphere the heat accumulatingy in. the portion of said' passaged means, through whichat leastthe air is conveyed,`means to impe] the fuelfromthe container and through saidA system, said system having a fuel-delivery outlet discharging to, said passagedV means,V and means in the conductor for maintainingthe fuelpressure at said outlet greater than the fuelpressure within thepassaged means itself.

6. In combination, with passaged means through which the components of a fuel-air charge ai'econveyed tovan internal-combustion engine, a uidfuel conducting system including a container for cooled `fluid fuel and a conductor for such fuel and to which the'` container dis'- chargesand which itself discharges to said system and`V includes, with a` heat-receiving, radiator in heat-receiving proximityV tothe portion of said.y means through which atleastthe air-component is conveyed, a heat-discharge' radiator bothof which,I are Vrelatively aft .ofthe'point at',k which the conductor discharges to said system', means to impel-the fuel fromthe container and through the conductor, said conductor havingrelatively aft of said point, a fuel-delivery outlet discharging toY said` passaged. means, andmeans in the conductor for maintaining the fuel-pressure at. said outletgreater thany the fuel-pressure within the passaged means itself. v

OSCAR APPEL. 

